Google Calendar Stream Component

Available as of Camel version 2.23

The Google Calendar component provides access to Calendar via the Google Calendar Web APIs.

Google Calendar uses the OAuth 2.0 protocol for authenticating a Google account and authorizing access to user data. Before you can use this component, you will need to create an account and generate OAuth credentials. Credentials comprise of a clientId, clientSecret, and a refreshToken. A handy resource for generating a long-lived refreshToken is the OAuth playground.

Maven users will need to add the following dependency to their pom.xml for this component:

    <dependency>
            <groupId>org.apache.camel</groupId>
            <artifactId>camel-google-calendar</artifactId>
            <!-- use the same version as your Camel core version -->
            <version>x.x.x</version>
    </dependency>

URI Format

The Google Calendar Component uses the following URI format:

        google-calendar-stream://index?[options]

Google Calendar stream component options

The Google Calendar Stream component supports 3 options, which are listed below.

Name Description Default Type

configuration (advanced)

The configuration

GoogleCalendarStream Configuration

clientFactory (advanced)

The client Factory

GoogleCalendarClient Factory

basicPropertyBinding (advanced)

Whether the component should use basic property binding (Camel 2.x) or the newer property binding with additional capabilities

false

boolean

The Google Calendar Stream endpoint is configured using URI syntax:

google-calendar-stream:index

with the following path and query parameters:

Path Parameters (1 parameters):

Name Description Default Type

index

Specifies an index for the endpoint

String

Query Parameters (31 parameters):

Name Description Default Type

accessToken (consumer)

OAuth 2 access token. This typically expires after an hour so refreshToken is recommended for long term usage.

String

applicationName (consumer)

Google Calendar application name. Example would be camel-google-calendar/1.0

String

bridgeErrorHandler (consumer)

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

false

boolean

calendarId (consumer)

The calendarId to be used

primary

String

clientId (consumer)

Client ID of the calendar application

String

clientSecret (consumer)

Client secret of the calendar application

String

considerLastUpdate (consumer)

Take into account the lastUpdate of the last event polled as start date for the next poll

false

boolean

consumeFromNow (consumer)

Consume events in the selected calendar from now on

true

boolean

maxResults (consumer)

Max results to be returned

10

int

query (consumer)

The query to execute on calendar

String

refreshToken (consumer)

OAuth 2 refresh token. Using this, the Google Calendar component can obtain a new accessToken whenever the current one expires - a necessity if the application is long-lived.

String

scopes (consumer)

Specifies the level of permissions you want a calendar application to have to a user account. See https://developers.google.com/calendar/auth for more info.

List

sendEmptyMessageWhenIdle (consumer)

If the polling consumer did not poll any files, you can enable this option to send an empty message (no body) instead.

false

boolean

exceptionHandler (consumer)

To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this option is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored.

ExceptionHandler

exchangePattern (consumer)

Sets the exchange pattern when the consumer creates an exchange.

ExchangePattern

pollStrategy (consumer)

A pluggable org.apache.camel.PollingConsumerPollingStrategy allowing you to provide your custom implementation to control error handling usually occurred during the poll operation before an Exchange have been created and being routed in Camel.

PollingConsumerPoll Strategy

basicPropertyBinding (advanced)

Whether the endpoint should use basic property binding (Camel 2.x) or the newer property binding with additional capabilities

false

boolean

synchronous (advanced)

Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported).

false

boolean

backoffErrorThreshold (scheduler)

The number of subsequent error polls (failed due some error) that should happen before the backoffMultipler should kick-in.

int

backoffIdleThreshold (scheduler)

The number of subsequent idle polls that should happen before the backoffMultipler should kick-in.

int

backoffMultiplier (scheduler)

To let the scheduled polling consumer backoff if there has been a number of subsequent idles/errors in a row. The multiplier is then the number of polls that will be skipped before the next actual attempt is happening again. When this option is in use then backoffIdleThreshold and/or backoffErrorThreshold must also be configured.

int

delay (scheduler)

Milliseconds before the next poll. You can also specify time values using units, such as 60s (60 seconds), 5m30s (5 minutes and 30 seconds), and 1h (1 hour).

500

long

greedy (scheduler)

If greedy is enabled, then the ScheduledPollConsumer will run immediately again, if the previous run polled 1 or more messages.

false

boolean

initialDelay (scheduler)

Milliseconds before the first poll starts. You can also specify time values using units, such as 60s (60 seconds), 5m30s (5 minutes and 30 seconds), and 1h (1 hour).

1000

long

runLoggingLevel (scheduler)

The consumer logs a start/complete log line when it polls. This option allows you to configure the logging level for that.

TRACE

LoggingLevel

scheduledExecutorService (scheduler)

Allows for configuring a custom/shared thread pool to use for the consumer. By default each consumer has its own single threaded thread pool.

ScheduledExecutor Service

scheduler (scheduler)

To use a cron scheduler from either camel-spring or camel-quartz component

none

String

schedulerProperties (scheduler)

To configure additional properties when using a custom scheduler or any of the Quartz, Spring based scheduler.

Map

startScheduler (scheduler)

Whether the scheduler should be auto started.

true

boolean

timeUnit (scheduler)

Time unit for initialDelay and delay options.

MILLISECONDS

TimeUnit

useFixedDelay (scheduler)

Controls if fixed delay or fixed rate is used. See ScheduledExecutorService in JDK for details.

true

boolean

Spring Boot Auto-Configuration

When using Spring Boot make sure to use the following Maven dependency to have support for auto configuration:

<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-google-calendar-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

The component supports 15 options, which are listed below.

Name Description Default Type

camel.component.google-calendar-stream.basic-property-binding

Whether the component should use basic property binding (Camel 2.x) or the newer property binding with additional capabilities

false

Boolean

camel.component.google-calendar-stream.client-factory

The client Factory. The option is a org.apache.camel.component.google.calendar.GoogleCalendarClientFactory type.

String

camel.component.google-calendar-stream.configuration.access-token

OAuth 2 access token. This typically expires after an hour so refreshToken is recommended for long term usage.

String

camel.component.google-calendar-stream.configuration.application-name

Google Calendar application name. Example would be "camel-google-calendar/1.0"

String

camel.component.google-calendar-stream.configuration.calendar-id

The calendarId to be used

primary

String

camel.component.google-calendar-stream.configuration.client-id

Client ID of the calendar application

String

camel.component.google-calendar-stream.configuration.client-secret

Client secret of the calendar application

String

camel.component.google-calendar-stream.configuration.consider-last-update

Take into account the lastUpdate of the last event polled as start date for the next poll

false

Boolean

camel.component.google-calendar-stream.configuration.consume-from-now

Consume events in the selected calendar from now on

true

Boolean

camel.component.google-calendar-stream.configuration.index

Specifies an index for the endpoint

String

camel.component.google-calendar-stream.configuration.max-results

Max results to be returned

10

Integer

camel.component.google-calendar-stream.configuration.query

The query to execute on calendar

String

camel.component.google-calendar-stream.configuration.refresh-token

OAuth 2 refresh token. Using this, the Google Calendar component can obtain a new accessToken whenever the current one expires - a necessity if the application is long-lived.

String

camel.component.google-calendar-stream.configuration.scopes

Specifies the level of permissions you want a calendar application to have to a user account. See https://developers.google.com/calendar/auth for more info.

List

camel.component.google-calendar-stream.enabled

Whether to enable auto configuration of the google-calendar-stream component. This is enabled by default.

Boolean

Consumer

The consumer will poll by default with maxResults equals to 5.

For example

from("google-calendar-stream://test?markAsRead=true&delay=5000&maxResults=5").to("mock:result");

This route will consume the next five events starting from the date of polling.